| From | danielfsantos@att ... | Subject | [PATCH v5 6/9] bug.h: Prevent double evaulation of in BUILD_BUG_ON | Date | Tue, 13 Nov 2012 16:13:38 -0600 |
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When calling BUILD_BUG_ON in an optimized build using gcc 4.3 and later, the condition will be evaulated twice, possibily with side-effects. This patch eliminates that error.
Signed-off-by: Daniel Santos <daniel.santos@pobox.com> --- include/linux/bug.h | 5 +++-- 1 files changed, 3 insertions(+), 2 deletions(-)
diff --git a/include/linux/bug.h b/include/linux/bug.h index 1b2465d..ccd44ce 100644 --- a/include/linux/bug.h +++ b/include/linux/bug.h @@ -58,8 +58,9 @@ struct pt_regs; extern int __build_bug_on_failed; #define BUILD_BUG_ON(condition) \ do { \ - ((void)sizeof(char[1 - 2*!!(condition)])); \ - if (condition) __build_bug_on_failed = 1; \ + bool __cond = !!(condition); \ + ((void)sizeof(char[1 - 2*!!(__cond)])); \ + if (__cond) __build_bug_on_failed = 1; \ } while(0) #endif -- 1.7.3.4
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